Tokyo’s three nonnuclear principles prevent entry; some say it’s time for change
TOKYO — In the coming days, a U.S. nuclear-powered ballistic missile submarine (SSBN) is expected to make a port call in South Korea for the first time since 1981.
The visit was agreed upon between U.S. President Joe Biden and South Korean President Yoon Suk Yeol when the two signed the so-called Washington Declaration at the White House on April 26. The aim is to enhance the “regular visibility” of strategic assets in the Korean Peninsula.
While the details of the visit are a tightly held secret, the USS Maine is expected to make a port call to Fleet Activities Chinhae, a U.S. naval base near the southern city of Busan, in mid-May.
But the Ohio-class submarine will not be stopping in Yokosuka or Sasebo, the U.S. Navy’s two bases in Japan. This is due to Japan’s “three nonnuclear principles,” a national policy Tokyo has held since 1967, when Prime Minister Eisaku Sato pledged that Japan “shall neither possess nor manufacture nuclear weapons, nor shall it permit their introduction into Japanese territory.”
Some lawmakers and analysts have noted that there may be room to alter the third element, about not permitting entry. It was originally included in the principles to show a wary public that Tokyo will not allow the U.S. military to deploy or transit nuclear weapons through Japanese territory, after Okinawa was returned to Japan in 1972.
The ballistic missile submarine’s visit to South Korea may ignite a fresh debate on Japan’s “almost religious” rejection of nuclear weapons, analysts said. The U.S. sent an SSBN to South Korea 35 times in the 1970s and ’80s, nuclear expert Hans Kristensen wrote in an article for the Federation of American Scientists in 2011. The visit of the USS Robert E Lee in March 1981 was the last time.
Tetsuro Kuroe, a former administrative vice minister of defense on Japan, said it is time for Japan to have discussions on the topic.
“The three nonnuclear principles are, in effect, four principles,” he told Nikkei Asia: “Japan shall not possess, nor manufacture, nor allow entry, nor ‘discuss’ nuclear weapons.”
Kuroe said that while he supports “99%” of what was written in Japan’s National Security Strategy and two supporting documents published in December 2022, the sole area that he feels is unaddressed is nuclear. Faced with North Korea’s missile launches and Russian President Vladimir Putin’s open threats to use tactical nuclear weapons, the National Security Strategy only notes that Japan will continue to observe the three nonnuclear principles.
A group of Japanese former defense officials, including Kuroe, has issued a policy proposal suggesting that Japan discuss reviewing the three principles, without viewing doing so as taboo. Noting that the U.S. does not have the means to counter China’s intermediate-range nuclear missiles, the study group said, “Japan cannot protect its national security by merely sticking to the three nonnuclear principles as a national credo.”
Retired Gen. Ryoichi Oriki, who chaired the study group, told Nikkei Asia, “China is expected to have 1,500 nuclear weapons by 2035. It is catching up to be a nuclear power on par with the U.S. and Russia. Japan needs to think of what to do in this new environment.”
Oriki, a former top officer in the Self-Defense Forces, said Japan has “almost religiously” avoided discussion on nuclear weapons. But he pointed to the debate in South Korea to possess its own nuclear weapons as a new shift in the region. “If both Koreas are nuclear states, that changes the whole dynamic,” he said.
The U.S. Navy has 14 Ohio-class SSBNs, each able to carry 20 Trident II missiles. Their stealth makes them the most survivable leg of America’s nuclear triad, offering advantages over land-based intercontinental ballistic missiles and strategic bombers.
Due to their secrecy and to sensitivity over nuclear weapons, American SSBNs rarely make foreign port calls. One of the few exceptions is Scotland, where SSBNs sometimes surface at the Clyde Naval Base in Faslane.
From an operational standpoint, the SSBN’s visit to South Korea offers no merit. If the submarine were to launch a missile, it would have to do so from out at sea.
Former Pentagon official Elbridge Colby called the port call “meaningless” in a recent webinar hosted by the Institute for Corean-American Studies.
“A ballistic missile submarine can launch a … missile from anywhere in the ocean and hit a target in China or Russia or North Korea. Its function is to hide, so going to a forward port, if anything, makes it more vulnerable because it’s within the range of Chinese aircraft and missiles. It really adds nothing,” the former deputy assistant secretary of defense for strategy and force development said.
Bonji Ohara, a senior fellow at the Sasakawa Peace Foundation, said the port call may reflect a desire on the U.S. side to discourage South Korea from pursuing its own nuclear program. “By publicly showing American nuclear presence, it wants to reassure that extended deterrence is working.”
Ohara noted that Prime Minister Fumio Kishida, whose constituency is in Hiroshima, the site of a nuclear attack in 1945, may be reluctant to change the three principles. But he pointed out that an SSBN port call may be much less politically toxic than deploying U.S. intermediate-range nuclear missiles in Japan.
Even though such a port call would infringe on the nonintroduction of nuclear weapons stipulated in the three principles, “the U.S. is not going to actually launch a missile from the port. It is for show,” Ohara said. “The resistance in Japan to such a visit should be smaller than other moves.”
Kuroe, the former defense official, suggested that Kishida have Japan simultaneously join the Treaty on the Prohibition of Nuclear Weapons as an observer and begin a review of the three principles. That way, the prime minister can express to the world Japan’s quest for a future without nuclear weapons and still address the nuclear realities of today.